The term biosensor is commonly referred to as a measuring device that combines a biological sensing part in close proximity to a non-biological transducer which converts the biochemical information produced in the biological part into a measurable signal.
The most commonly employed transducer in current biosensor instruments (e.g. a clinical analyser) is electrochemically based. The analyser is often used in connection with a biosensor unit (one-time use), which before operation, is connected to the analyser. The biosensor unit contains both the biological and the electronic part. It has turned out that there is a significant cost of designing and fabricating a custom integrated biosensor unit that includes both the biological sensing part and the necessary electronic elements. One major reason for this is that the materials and methods used for electronic components require very high temperatures, which temperature levels are incompatible with the fabrication of the biological part. It has turned out to be difficult to combine these contradicting demands of the devices to be manufactured. In a recently invented biosensor technology (disclosed in EP application 01952081.6) thermal flow has been used as transducer, circumventing the above mentioned drawbacks with electrochemical detection. However, it has turned out that this transducer technology could have a drawback of being sensitive, in some cases, to interference from rapid and sudden temperature and heat radiation changes in the environment and therefore making it less useful in these cases.